Voicemail issue with 'The Atlantic Telegraph' on iPhone

When I call anyone in my contacts who has a phone number set as “other,” it doesn’t dial them and instead immediately plays an audio recording of “The Atlantic Telegraph” by William Howard Russell (I had to google phrases in the book to figure out what it was playing). Why is this happening?? I assume changing what their numbers are classified as will fix this, but I just want to know why this is happening!!

[Re-Titled by Moderator]